Illuminating appliance.



- A. w. BEUTTELL.

ILLUMINATING APPLIANCE.

APPLICATION FILED 920.21, 1912. 1, 174,470. Patented Mar. 7, 1916,

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ILLUMINATING APPLIANCE.

APPLICATION FILED 05c. 21, 1912.

Patented Mar. 16.

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ALFRED W. BEUTTELL, 0F STREATHAM, LONDON, ENGLAND.

Specification of Letters Patent.

PatentedMar. 7,1916.

Application filed. December 21, 1912. Serial No. 737,956.

To all whom it may concern:

Be it known that I, ALFRED WILLIAM BEUTTEL a subject of the King of Great Britain,

. a uniform concave cross-section throughrection as or in a diflerent direction from the direction in whlch the corrugations onv obliquely corrugated out their length which are commonly used in combination with linear or straight sources of light, for instance with double ended lamps of the straight filamenttype.

In the specification accompanying my copending application for Letters Patent, Se

rial No. 737 ,957, filed December 21st, 1912, I have described an improved construction of reflectors, of the kind referred to, and according to which the reflecting surfaces are persing the striae or streaks of light Which commonly occur in thelight reflected from such reflectors when they are'formed with smooth surfaces. According to the present invention instead of or in addition to using such corrugated reflecting surface I employ in front of the reflector and light source a glass screen or plate or strip of glass or its equiva-x lent having one surface provided with raised or depressed portions preferably in the form of oblique corrugations. These raised and depressed portions or corrugations 1n the glass or screen may extend in the same d1- the reflector extend, should the latter be corrugated and the corrugations on one side of the glass or screen may extend in the samedirection as or in a different direction from the direction in which the corrugations on the other side of the glass orscreen extend should said screen be corrugated on both sides. The efl'ect-of such a glass screen is similar to that of the corrugated reflector above referred to, with the difference how ever that the'streaks of light emanating from the reflector are dispersed by the corrugated glass screen by refraction, the streaks or successive portions of them being displaced alternately in opposite directions. y increasing or decreasing the depth of the corrugations I may obviously obtain any for the purpose of dis invention- Figs. 5

desired degree of dispersion; the corrugations or Wave-like formation being of any desired form or type and of any desired obliquity. The glass screen or strip, corrugated as aforesaid, may be either flat or curved 1n cross-section or any desired form other than flat. Also instead of or inaddition to locating and using the corrugated glass screen in front of the reflector I may form the reflector itself of such corrugated glass silvered or treated in any suitable man. ner on the back thereofto form a reflecting. surface. I I I v According to this last modification of the present invention the refraction or dispelsion referred to will take place at the corrugated surface 'thereofbefore the radiation from thelight source or reflecting surface'instead of or in addition to the refraction or dispersion takingplace afterward.

Referring to the accompanying drawings Figure l is a plan view of a-flat glass screen accordingv o the present invention, corruface. The same figurewill also serve to represent the appearanceof a screencorru gated on both sides thereof in the samedirection. ,If,"however,,one of these improved screens: be corrugated" on opposite sides thereof in opposite directions, this Fig. 1 will also-represent thedirection ofjthecorreaches the reflector rugations of the oppositeside thereof if the;

screen be turned over. Fig. .2 is an elevational sectional View-of Fig. -1 on the line 2-2. where the screen is corrugated in one direction on one side only. Fig. 3 is a similar view Where the corrugations are formedon both sides of the glass screen. Fig. 4 is a sectionalview of an illuminating device having a concentrating reflector and 'pro-, vided' with a screen according to the present and 6 are sectional views of sheets of glass corrugated according to the present invention and silvered or treated on the back thereof to form reflectors or reflecting surfaces. Fig. 7 is a sectional view of an example of an illuminating appliance provided with such a reflector according to the present'invention. Fig. 8 is a View ofv a lamp of the straight filament type. 1

Referring now to Fig. 4:, the illuminating appliance consists of a reflector body B pro vided on the concave side thereof with a separate reflector or reflecting surfacev A 80 I gated in one direction only on its upper surwhich for the sake of example, I have shown as a concentrating or intensifying reflector having a smooth surface or one liable to produce in practice accidental variations in the illumination therefrom. Within the concavity of the reflector A is located a lamp or light source 0, which is preferably an incandescent lamp of the straight filament type,that is, a lamp which provides an eX- tended uni-directional source of light, and on the opposite side thereof the curved glass screen D shown for the sake of example corrugated on both sides thereof. Lamps of the straight filament type are shown in Fig. 8 and also in my Patent No. 1,107 ,650, granted August 18th, 1914. This lamp C. is supported in position on the reflector body by any suitable holding means indicatedas C. Obviously, however, screens according to the present invention may be of any other desired or suitable size or shape according to the particular appliance in conjunction with which they are used.

Referring now to Fig. 5 the glass sheet is shown corrugated on one side only and on the opposite side is provided with a reflecting surface, shown by the thick line A.

Similarly in Fig. 6 the thick line A rep-. resents the reflecting surface provided on one side of the glass sheet which in this figure, however, is shown corrugated on both sides thereof.

Referring now to Fig. 7 the reflector body B incloses the concentrating or intensifying reflector E made according to the present invention and of a corrugated glass sheet corrugated on one side thereof in accordance with Fig. 5. Thereflector E is provided with the reflecting surface A on that side of the corrugated glass sheet farthest removed from the source of light C. The illuminating appliance shown in Fig. 7 is chosen only for the sake of example, it being understood that any desired form of illuminating appliance may be made with reflectors according to the present invention. In this last modification as shown in Fig. 7 the radiation from the light source 0 falling upon the reflector E is refracted at the corrugated surface of the reflector, is then reflected at the surface A and is again refracted in passing back through the said corrugated surface. Also any such illuminating appliances may be provided further if desired with separate corrugated glass screens D as shown in Fig. 4:.

From an inspection of the drawings it will be apparent that each of the glass screens or other transparent light refracting member preferably extends longitudinally, that it may be curved in cross-section throughout its length and that it is provided with raised or depressed or corrugated portions on one or both surfaces and that these last mentioned portions extend diagonally to the longitudinal aXisof the screen and also diagonally to the source of light which is preferably comprised of one or more incandescing filament sections.

The improvements herein set forth are not limited to the precise construction and arrangement shown and described, as they may be embodied in various forms and modifications Without departing from the spirit and scope of the invention.

\Vhat I claim is:

1. In an illuminating appliance of the class described the combination with an extended uni-directional source of light and a reflector concave in cross-section located behind said source of light, of a plate of transparent material provided with corrugations obliquely disposed to the direction of the source of light for the purpose described of slightly blending by refraction the approximate rays from the source of light and the reflector while substantially maintaining the direction of the same.

2. The combination with an incandescent electric lamp of the straight filament type and a holder therefor, of a member providing a reflecting surface behind the lamp, which reflecting surface is concave in crosssection, there being a transparent medium located in front of'the reflecting surface and in. the path of the light rays, said transparent medium having surface corrugations that extend diagonally to the filament section or sections of said lamp. 7

3. An illuminating appliance of the class described having a reflector concave in cross section, an incandescent electric lamp for producing a straight line source of light, means for supporting the electric lamp on the concave side of the reflector, and a trans parent plate screen having parallel surface corrugations which are obliquely disposed to the source of light.

This specification signed and witnessed this 3rd day of December, A. D. 1912.

ALFRED lV. BEUTTELL.

Signed in the presence of- AUSTIN B. BOLEMAN, EDWIN A. PACKARD.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Batents, Washington D. 0. 

